Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovery of a fundamental limit to the evolution of the genetic code

03.05.2016

A study performed at IRB Barcelona offers an explanation as to why the genetic code, the dictionary used by organisms to translate genes into protein, stopped growing 3,000 million years ago.

Nature is constantly evolving--its limits determined only by variations that threaten the viability of species. Research into the origin and expansion of the genetic code* are fundamental to explain the evolution of life.


This is a 3-D representation of a transfer RNA (tRNA). These molecules are crucial for the translation of genes into proteins and they are also the reason why the genetic code cannot exceed 20 amino acid.

(Author: Pablo Dans, IRB Barcelona)

In Science Advances, a team of biologists specialised in this field explain a limitation that put the brakes on the further development of the genetic code, which is the universal set of rules that all organisms on Earth use to translate genetic sequences of nucleic acids (DNA and RNA) into the amino acid sequences that comprise the proteins that undertake cell functions.

Headed by ICREA researcher Lluís Ribas de Pouplana at the Institute for Research in Biomedicine (IRB Barcelona) and in collaboration with Fyodor A. Kondrashov, at the Centre for Genomic Regulation (CRG) and Modesto Orozco, from IRB Barcelona, the team of scientists has demonstrated that the genetic code evolved to include a maximum of 20 amino acids and that it was unable to grow further because of a functional limitation of transfer RNAs--the molecules that serve as interpreters between the language of genes and that of proteins.

This halt in the increase in the complexity of life happened more than 3,000 million years ago, before the separate evolution of bacteria, eukaryotes and archaebacteria, as all organisms use the same code to produce proteins from genetic information.

The authors of the study explain that the machinery that translates genes into proteins* is unable to recognise more than 20 amino acids because it would confuse them, which would lead to constant mutations in proteins and thus the erroneous translation of genetic information "with catastrophic consequences", in Ribas' words. "Protein synthesis based on the genetic code is the decisive feature of biological systems and it is crucial to ensure faithful translation of information," says the researcher.

A limitation imposed by shape

Saturation of the genetic code has its origin in transfer RNAs (tRNAs*), the molecules responsible for recognising genetic information and carrying the corresponding amino acid to the ribosome, the place where chain of amino acids are made into proteins following the information encoded in a given gene. However, the cavity of the ribosome into which the tRNAs have to fit means that these molecules have to adopt an L-shape, and there is very little possibility of variation between them.

"It would have been to the system's benefit to have made new amino acids because, in fact, we use more than the 20 amino acids we have, but the additional ones are incorporated through very complicated pathways that are not connected to the genetic code. And there came a point when Nature was unable to create new tRNAs that differed sufficiently from those already available without causing a problem with the identification of the correct amino acid. And this happened when 20 amino acids were reached," explains Ribas.

Application in synthetic biology

One of the goals of synthetic biology is to increase the genetic code and to modify it to build proteins with different amino acids in order to achieve novel functions. For this purpose, researchers use organisms such as bacteria in highly controlled conditions to make proteins of given characteristics. "But this is really difficult to do and our work demonstrates that the conflict of identify between synthetic tRNAs designed in the lab and existing tRNAs has to be avoided if we are to achieve more effective biotechnological systems," concludes the researcher.

###

This study has been funded by the Ministry of the Economy and Competitiveness, the Generalitat de Catalunya, the European Research Council (ERC) and the Howard Hughes Medical Institute in the US.

Reference article:

Saturation of recognition elements blocks evolution of new tRNA identities

Adélaïde Saint-Léger, Carla Bello-Cabrera, Pablo D. Dans, Adrian Gabriel Torres, Eva Maria Novoa, Noelia Camacho, Modesto Orozco, Fyodor A. Kondrashov, and Lluís Ribas de Pouplana

Science Advances (29 April 2016). DOI: 10.1126/sciadv.1501860

Media Contact

Sònia Armengou
armengou@irbbarcelona.org
34-618-294-070

http://www.irbbarcelona.org 

Sònia Armengou | EurekAlert!

More articles from Life Sciences:

nachricht BigH1 -- The key histone for male fertility
14.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Guardians of the Gate
14.12.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Plasmonic biosensors enable development of new easy-to-use health tests

14.12.2017 | Health and Medicine

New type of smart windows use liquid to switch from clear to reflective

14.12.2017 | Physics and Astronomy

BigH1 -- The key histone for male fertility

14.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>